Digital imaging devices capture images over a wide range of illuminants. Typically the digital imaging device will color correct the captured image with a different correction mask for each of the different illuminants. This requires the digital imaging device to store a large number of different correction masks, for example 15 different correction masks. These correction masks take up considerable space inside the digital imaging device.
In addition, calibrating each camera module over the wide range of different illuminant takes considerable time. The camera module must be properly aligned with the camera's optical axis perpendicular to a uniformly screen illuminated at the proper color temperature. One or more exposures are taken using each of the different illuminant choices. The different images are then used to create the different illuminant-dependent calibration data.
The time required to calibrate the camera module at each of the different color temperature illuminants and the memory needed to store each illuminant-dependent calibration data are the largest issues with current calibration methods.